On the use of complex numbers in quantum models for information retrieval

Guido Zuccon, Benjamin Piwowarski, Leif Azzopardi

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

7 Citations (Scopus)


Quantum-inspired models have recently attracted increasing attention in Information Retrieval. An intriguing characteristic of the mathematical framework of quantum theory is the presence of complex numbers. However, it is unclear what such numbers could or would actually represent or mean in Information Retrieval. The goal of this paper is to discuss the role of complex numbers within the context of Information Retrieval. First, we introduce how complex numbers are used in quantum probability theory. Then, we examine van Rijsbergen's proposal of evoking complex valued representations of informations objects. We empirically show that such a representation is unlikely to be effective in practice (confuting its usefulness in Information Retrieval). We then explore alternative proposals which may be more successful at realising the power of complex numbers.
Original languageEnglish
Title of host publicationICTIR'11 Proceedings of the Third international conference on Advances in information retrieval theory
Place of PublicationBerlin, Heidelberg
Number of pages5
ISBN (Print)978-3-642-23317-3
Publication statusPublished - 12 Sep 2011
Externally publishedYes

Publication series

NameLecture Notes in Computer Science


  • information retrieval
  • search strategies
  • quantum probability theory

Cite this